Commented Issue: Missing Component DeploymentCatalog [14602]

I moved some code from the 4.0 framework to the 4.5 framework and the object System.ComponentModel.Composition.Hosting.DeploymentCatalog doesn't exist anymore.
Comments: I copied the older DLLs from another project and now I get this error: {System.IO.FileNotFoundException: Could not load file or assembly 'System.Threading.Tasks, Version=2.5.11.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a' or one of its dependencies. The system cannot find the file specified. File name: 'System.Threading.Tasks, Version=2.5.11.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a'} When I new up a Deployment Catalog. The version in the GAC is 4.0.0.0. The code is simple: aggregateCatalog = new AggregateCatalog(); aggregateCatalog.Catalogs.Add(new DeploymentCatalog()); Any idea on what to do?